Bipolar transistors are widely used in semiconductor devices. In some electronic circuit applications it is desirable to utilize bipolar transistors and CMOS devices.
Although it has been well known for a long time that reducing the size of electronic components is desirable, the practical means of doing so are not easily determined and do not yield predictable results.
In the semiconductor field, the desire to continually reduce the size of semiconductor devices has not been a progression of minor steps aimed at reducing size of various aspects of a semiconductor but has required substantial changes in the basic structure as well as in the manner of making the structure.
For a number of reasons that include reduction of semiconductor size, field effect transistors fabricated with CMOS technology have become standard for memory circuits where a large number of semiconductor devices are packed onto an integrated circuit chip. Use of CMOS technology has generally allowed a reduction of semiconductor device size from that achieved using bipolar transistor devices.
There are a number of circuit applications where increasingly large drive currents at ever increasing frequencies are to be handled. In such applications the current handling capacity of bipolar transistors is desirable although their size is a drawback. Additionally, the bipolar transistors may not be the best solution to all of the operational constraints of a particular circuit.